Critical Mass

“Did I ever tell you,” said Harry Purvis modestly, “about the time I prevented the evacuation of southern England?”

“You did not,” said Charles Willis, “or if you did, I slept through it.”

“Well, then,” continued Harry, when enough people had gathered round him to make a respectable audience. “It happened two years ago at the Atomic Energy Re­search Establishment near Clobham. You all know the place, of course. But I don’t think I’ve mentioned that I worked there for a while, on a special job I can’t talk about.”

“That makes a nice change,” said John Wyndham, without the slightest effect.

“It was on a Saturday afternoon,” Harry began. “A beautiful day in late spring. There were about six of us scientists in the bar of the “Black Swan”, and the windows were open so that we could see down the slopes of Clob­ham Hill and out across the country to Upchester, about thirty miles away. It was so clear, in fact, that we could pick out the twin spires of Upchester Cathedral on the horizon. You couldn’t have asked for a more peaceful day.

“The staff from the Establishment got on pretty well with the locals, though at first they weren’t at all happy about having us on their doorsteps. Apart from the na­ture of our work, they’d believed that scientists were a race apart, with no human interests. When we’d beaten them up at darts a couple of times, and bought a few drinks, they changed their minds. But there was still a certain amount of half-serious leg-pulling, and we were always being asked what we were going to blow up next.

“On this afternoon there should have been several more of us present, but there’d been a rush job in the Radio-isotopes Division and so we were below strength. Stanley Chambers, the landlord, commented on the absence of some familiar faces.

“ ‘What’s happened to all your pals today?” he asked my boss, Dr. French.

“ “They’re busy at the works,’ French replied—we al­ways called the Establishment “the Works”, as that made it seem more homely and less terrifying. ‘We had to get some stuff out in a hurry. They’ll be along later.’

“ ‘One day,’ said Stan severely, ‘you and your friends are going to let out something you won’t be able to bottle up again. And then where will we all be?’

“ ‘Half-way to the Moon,’ said Dr. French. I’m afraid it was rather an irresponsible sort of remark, but silly questions like this always made him lose patience.

“Stan Chambers looked over his shoulder as if he was judging how much of the hill stood between him and Clobham. I guessed he was calculating if he’d have time to reach the cellar—or whether it was worth trying any­way.

“ ‘About these—isotopes—you keep sending to the hos­pitals,’ said a thoughtful voice. ‘I was at St. Thomas’ last week, and saw them moving some around in a lead safe that must have weighed a ton. It gave me the creeps, won­dering what would happen if someone forgot to handle it properly.’

“ ‘We calculated the other day,’ said Dr. French, obvi­ously still annoyed at the interruption to his darts, ‘that there was enough uranium in Clobham to boil the North Sea.’

“Now that was a silly thing to say: and it wasn’t true, either. But I couldn’t very well reprimand my own boss, could I?

“The man who’d been asking these questions was sit­ting in the alcove by the window, and I noticed that he was looking down the road with an anxious expression.

“ “The stuff leaves your place on trucks, doesn’t it?’ he asked, rather urgently.

“ ‘Yes: a lot of isotopes are short-lived, and so they’ve got to be delivered immediately.’

“ ‘Well, there’s a truck in trouble down the hill. Would it be one of yours?’

“The dart-board was forgotten in the general rush to the window. When I managed to get a good look, I could see a large truck, loaded with packing cases, careering down the hill about a quarter of a mile away. From time to time it bounced off one of the hedges: it was obvious that the brakes had failed and the driver had lost con­trol. Luckily there was no on-coming traffic, or a nasty accident would have been inevitable. As it was, one looked probable.

“Then the truck came to a bend in the road, left the pavement, and tore through the hedge. It rocked along with diminishing speed for fifty yards, jolting violently over the rough ground. It had almost come to rest when it encountered a ditch and, very sedately, canted over on to one side. A few seconds later the sound of splintering wood reached us as the packing cases slid off to the ground.

“ That’s that,’ said someone with a sigh of relief. ‘He did the right thing, aiming for the hedge. I guess he’ll be shaken up, but he won’t be hurt.’

“And then we saw a most perplexing sight. The door of the cab opened, and the driver scrambled out. Even from this distance, it was clear that he was highly agitated —though, in the circumstances, that was natural enough.

But he did not, as one would have expected, sit down to recover his wits. On the contrary: he promptly took to his heels and ran across the field as if all the demons of hell were after him.

“We watched open-mouthed, and with rising apprehen­sion, as he dwindled down the hill. There was an ominous silence in the bar, except for the ticking of the clock that Stan always kept exactly ten minutes fast. Then some­one said ‘D’you think we’d better stay? I mean—it’s only half a mile. . . .’

“There was an uncertain movement away from the win­dow. Then Dr. French gave a nervous little laugh.

;< ‘We don’t know if it is one of our trucks,’ he said. ‘And anyway, I was pulling your legs just now. It’s com­pletely impossible for any of this stuff to explode. He’s just afraid his tank’s going to catch fire.’

“‘Oh yes?’ said Stan. ‘Then why’s he still running? He’s half-way down the hill now.’

“‘I know!’ suggested Charlie Evan, from the Instru­ments Section. ‘He’s carrying explosives, and is afraid they’re going to go up.’

“I had to scotch that one. ‘There’s no sign of a fire, so what’s he worried about now? And if he was carrying explosives, he’d have a red flag or something.’

“‘Hang on a minute,’ said Stan. ‘I’ll go and get my glasses.’

“No one moved until he came back: no one, that is, except the tiny figure far down the hill-side, which had now vanished into the woods without slackening its speed. “Stan stared through the binoculars for an eternity. At last he lowered them with a grunt of disappointment.

“ ‘Can’t see much,’ he said. ‘The truck’s tipped over in the wrong direction. Those crates are all over the place— some of them have busted open. See if you can make anything of it.’

“French had a long stare, then handed the glasses to me. They were a very old-fashioned model, and didn’t help much. For a moment it seemed to me that there was a curious haziness about some of the boxes—but that didn’t make sense. I put it down to the poor condition of the lenses.

“And there, I think, the whole business would have fizzled out if those cyclists hadn’t appeared. They were puffing up the hill on a tandem, and when they came to the fresh gap in the hedge they promptly dismounted to see what was going on. The truck was visible from the road and they approached it hand in hand, the girl obvi­ously hanging back, the man telling her not to be nerv­ous. We could imagine their conversation: it was a most touching spectacle.

“It didn’t last long. They got to within a few yards oil the truck—and then departed at high speed in opposite directions. Neither looked back to observe the other’s progress; and they were running, I noticed, in a most peculiar fashion.

“Stan, who’d retrieved his glasses, put them down with] a shaky hand.

“ ‘Get out the cars!’ he said.

“ ‘But—’ began Dr. French.

“Stan silenced him with a glare. ‘You damned scientists!’ he said, as he slammed and locked the till (even at a moment like this, he remembered his duty) ‘I knew you’d do it sooner or later.’

“Then he was gone, and most of his cronies with him, They didn’t stop to offer us a lift.

“ ‘This is perfectly ridiculous!’ said French. ‘Before we know where we are, those fools will have started a panic and there’ll be hell to pay.’

“I knew what he meant. Someone would tell the po­lice: cars would be diverted away from Clobham: the telephone lines would be blocked with calls—it would be like the Orson Welles “War of the Worlds” scare back in 1938. Perhaps you think I’m exaggerating, but you can never underestimate the power of panic. And people were scared, remember, of our place, and were half-expecting something like this to happen.

“What’s more, I don’t mind telling you that by this time we weren’t any too happy ourselves. We were simply un> able to imagine what was going on down there by the wrecked truck, and there’s nothing a scientist hates more than being completely baffled.

“Meanwhile I’d grabbed Stan’s discarded binoculars and had been studying the wreck very carefully. As I looked, a theory began to evolve in my mind. There was some—aura—about those boxes. I stared until my eyes began to smart, and then said to Dr. French: ‘I think I know what it is. Suppose you ring up Clobham Post Office and try to intercept Stan, or at least to stop him spreading rumours if he’s already got there. Say that everything’s under control—there’s nothing to worry about. While you’re doing that, I’m going to walk down to the truck and test my theory.’

“I’m sorry to say that no one offered to follow me. Though I started down the road confidently enough, after a while I began to be a little less sure of myself. I remembered an incident that’s always struck me as one of history’s most ironic jokes, and began to wonder if something of the same sort might not be happening now. There was once a volcanic island in the Far East, with a population of about 50,000. No one worried about the volcano, which had been quiet for a hundred years. Then, one day, eruptions started. At first they were minor, but they grew more intense hour by hour. The people started to panic, and tried to crowd aboard the few boats in harbor so that they could reach the mainland.

“But the island was ruled by a military commandant who was determined to keep order at all costs. He sent out proclamations saying that there was no danger, and he got his troops to occupy the ships so that there would be no loss of life as people attempted to leave hi over­loaded boats. Such was the force of his personality, and the example of his courage, that he calmed the multi­tude, and those who had been trying to get away crept shame-faced back to their homes, where they sat waiting for conditions to return to normal.

“So when the volcano blew up a couple of hours later, taking the whole island with it, there weren’t any sur­vivors at all. ...

“As I got near the truck, I began to see myself in the role of that misguided commandant. After all, there are some times when it is brave to stay and face danger, and others when the most sensible thing to do is to take to the hills. But it was too late to turn back now, and / was fairly sure of my theory.”

“I know,” said George Whiteley, who always liked to spoil Harry’s stories if he could. “It was gas.”

Harry didn’t seem at all perturbed at losing his cli­max.

“Ingenious of you to suggest it. That’s just what I did think, which shows that we can all be stupid at times.

“I’d got to within fifty feet of the truck when I stopped dead, and though it was a warm day a most unpleasant chill began to spread out from the small of my back. For I could see something that blew my gas theory to blazes and left nothing at all in its place.

“A black, crawling mass was writhing over the sur­face of one of the packing cases. For a moment I tried to pretend to myself that it was some dark liquid oozing from a broken container. But one rather well-known charac­teristic of liquids is that they can’t defy gravity. This thing was doing just that: and it was also quite obviously alive. From where I was standing, it looked like the pseudo pod of some giant amoeba as it changed its shape and thickness, and wavered to and fro over the side of the broken crate.

“Quite a few fantasies that would have done credit to Edgar Allan Poe flitted through my mind in those few seconds. Then I remembered my duty as a citizen and my pride as a scientist: I started to walk forward again, though in no great haste.

“I remember sniffing cautiously, as if I still had gas on the mind. Yet it was my ears, not my nose, that gave me the answer, as the sound from that sinister, seething mass built up around me. It was a sound I’d heard a million times before, but never as loud as this. And I sat down— not too close—and laughed and laughed and laughed, Then I got up and walked back to the pub.

“ ‘Well,’ said Dr. French eagerly, ‘what is it? We’ve got Stan on the line—caught him at the crossroads. But he won’t come back until we can tell him what’s hap­pening.’

“ Tell Stan,’ I said, ‘to rustle up the local apiarist, and bring him along at the same time. There’s a big job for him here.’

“ The local what?’ said French. Then his jaw dropped. •My God! You don’t mean. . . .’

“ ‘Precisely,’ I answered, walking behind the bar to see if Stan had any interesting bottles hidden away. “They’re settling down now, but I guess they’re still pretty annoyed. I didn’t stop to count, but there must be half a million bees down there trying to get back into their busted hives.’”

The Ultimate Melody

Have you ever noticed that, when there are twenty or thirty people talking together in a room, there are occa­sional moments when everyone becomes suddenly silent, so that for a second there’s a sudden, vibrating emptiness that seems to swallow up all sound? I don’t know how it affects other people, but when it happens it makes me feel cold all over. Of course, the whole thing’s merely caused by the laws of probability, but somehow it seems more than a mere coinciding of conversational pauses. It’s almost as if everybody is listening for something—they don’t know what. At such moments I say to myself:

But at my back I always hear

Time’s wmg6d chariot hurrying near. . . .

That’s how 7 feel about it, however cheerful the com­pany in which it happens. Yes, even if it’s in the “White Hart.”

It was like that one Wednesday evening when the place wasn’t quite as crowded as usual. The Silence came, as unexpectedly as it always does. Then, probably in a deliberate attempt to break that unsettling feeling of sus­pense, Charlie Willis started whistling the latest hit tune. I don’t even remember what it was. I only remember that it triggered off one of Harry Purvis’ most disturbing stories.

“Charlie,” he began, quietly enough. “That darn tune’s! driving me mad. I’ve heard it every time I’ve switched on; the radio for the last week.”

There was a sniff from John Christopher.

“You ought to stay tuned to the Third Programme. Then you’d be safe.”

“Some of us,” retorted Harry, “don’t care for an ex-j elusive diet of Elizabethan madrigals. But don’t let’s quar­rel about that, for heavens sake. Has it ever occurred to you that there’s something rather—fundamental—about hit tunes?”

“What do you mean?”

“Well, they come along out of nowhere, and then for weeks everybody’s humming them, just as Charlie did then. The good ones grab hold of you so thoroughly that you just can’t get them out of your head—they go round and round for days. And then, suddenly, they’ve van­ished again.”

“I know what you mean,” said Art Vincent. “There are some melodies that you can take or leave, but others stick like treacle, whether you want them or not.”

“Precisely. I got saddled that way for a whole week with the big theme from the finale of Sibelius Two—even went to sleep with it running round inside my head. Then there’s that ‘Third Man’ piece—da di da di daa, di da, di daa . . . look what that did to everybody.”

Harry had to pause for a moment until his audience had stopped zithering. When the last “Plonk!” had died away he continued:

“Precisely! You all felt the same way. Now what is there about these tunes that has this effect? Some of them are great music—others just banal, but they’ve ob­viously got something in common.”

“Go on,” said Charlie. “We’re waiting.”

“I don’t know what the answer is,” replied Harry.

“And what’s more, I don’t want to. For I know a man who found out.”

Automatically, someone handed him a beer, so that the tenor of his tale would not be disturbed. It always an­noyed a lot of people when he had to stop in mid-flight for a refill.

“I don’t know why it is,” said Harry Purvis, “that most scientists are interested in music, but it’s an undeniable fact. I’ve known several large labs that had their own amateur symphony orchestras—some of them quite good, too. As far as the mathematicians are concerned, one can think of obvious reasons for this fondness: music, par­ticularly classical music, has a form which is almost math­ematical. And then, of course, there’s the underlying theory—harmonic relations, wave analysis, frequency dis­tribution, and so on. It’s a fascinating study in itself, and one that appeals strongly to the scientific mind. More­over, it doesn’t—as some people might think-—preclude a purely aesthetic appreciation of music for its own sake.

“However, I must confess that Gilbert Lister’s interest in music was purely cerebral. He was, primarily, a phys­iologist, specialising in the study of the brain. So when I said that his interest was cerebral, I meant it quite lit­erally. ‘Alexander’s Ragtime Band’ and the Choral Sym­phony were all the same to him. He wasn’t concerned with the sounds themselves, but only what happened when they got past the ears and started doing things to the brain.

“In an audience as well educated as this,” said Harry, with an emphasis that made it sound positively insulting, “there will be no-one who’s unaware of the fact that much of the brain’s activity is electrical. There are, in fact, steady pulsing rhythms going on all the time, and they can be detected and analysed by modern instruments. This was Gilbert Lister’s line of territory. He could stick electrodes on your scalp and his amplifiers would draw your brainwaves on yards of tape. Then he could ex­amine them and tell you all sorts of interesting things about yourself. Ultimately, he claimed, it would be pos­sible to identify anyone from their encephalogram—to use the correct term—more positively than by finger­prints. A man might get a surgeon to change his skin, but if we ever got to the stage when surgery could change your brain—well, you’d have turned into somebody else, anyway, so the system still wouldn’t have failed.

“It was while he was studying the alpha, beta and other rhythms in the brain that Gilbert got interested in music. He was sure that there must be some connexion between musical and mental rhythms. He’d play music at various tempos to his subjects and see what effect it bad on their normal brain frequencies. As you might expect, it had a lot, and the discoveries he made led Gilbert on into more philosophical fields.

“I only had one good talk with him about his theories. It was not that he was at all secretive—I’ve never met a scientist who was, come to think of it—but he didn’t like to talk about his work until he knew where it was leading. However, what he told me was enough to prove that he’d opened up a very interesting line of territory, and there­after I made rather a point of cultivating him. My firm supplied some of his equipment, but I wasn’t averse to picking up a little profit on the side. It occurred to me that if Gilbert’s ideas worked out, he’d need a business manager before you could whistle the opening bar of the Fifth Symphony. . . .

“For what Gilbert was trying to do was to lay a scien­tific foundation for the theory of hit-tunes. Of course, he didn’t think of it that way: he regarded it as a pure re­search project, and didn’t look any further ahead than a paper in the Proceedings of the Physical Society. But I spotted its financial implications at once. They were quite breath-taking.

“Gilbert was sure that a great melody, or a hit tune, made its impression on the mind because in some way it fitted in with the fundamental electrical rhythms going on in the brain. One analogy he used was ‘It’s like a Yale key going into a lock—the two patterns have got to fit before anything happens.’

“He tackled the problem from two angles. In the first place, he took hundreds of the really famous tunes in classical and popular music and analyzed their structure— their morphology, as he put it. This was done automati­cally, in a big harmonic analyzer that sorted out all the frequencies. Of course, there was a lot more to it than this, but I’m sure you’ve got the basic idea.

“At the same time, he tried to see how the resulting patterns of waves agreed with the natural electrical vibra­tions of the brain. Because it was Gilbert’s theory—and this is where we get into rather deep philosophical waters —that all existing tunes were merely crude approxima­tions to one fundamental melody. Musicians had been groping for it down the centuries, but they didn’t know what they were doing, because they were ignorant of the relation between music and mind. Now that this had been unraveled, it should be possible to discover the Ultimate Melody.”

“Huh!” said John Christopher. “It’s only a rehash of Plato’s theory of ideals. You know—all the objects of our material world are merely crude copies of the ideal chair or table or what-have-you. So your friend was after the ideal melody. And did he find it?”

“I’ll tell you,” continued Harry imperturbably. “It took Gilbert about a year to complete his analysis, and then he started on the synthesis. To put it crudely, he built a machine that would automatically construct patterns of sound according to the laws that he’d uncovered. He had banks of oscillators and mixers—in fact, he modified an ordinary electronic organ for this part of the apparatus— which were controlled by his composing machine. In the rather childish way that scientists like to name their off­spring, Gilbert had called this device Ludwig.

“Maybe it helps to understand how Ludwig operated if you think of bun as a kind of kaleidoscope, working with sound rather than light. But he was a kaleidoscope set to obey certain laws, and those laws—so Gilbert believed— were based on the fundamental structure of the human mind. If he could get the adjustments correct, Ludwig would be bound, sooner or later, to arrive at the Ultimate Melody as he searched through all the possible patterns of music.

“I had one opportunity of hearing Ludwig at work, and! it was uncanny. The equipment was the usual nondescript mess of electronics which one meets in any lab: it might have been a mock-up of a new computer, a radar gun-sight, a traffic control system, or a ham radio. It was very hard to believe that, if it worked, it would put every com­poser in the world out of business. Or would it? Perhaps not: Ludwig might be able to deliver the raw material, but surely it would still have to be orchestrated.

“Then the sound started to come from the speaker, At first it seemed to me that I was listening to the five-finger exercises of an accurate but completely uninspired pupil. Most of the themes were quite banal: the machine would play one, then ring the changes on it bar after bar until it had exhausted all the possibilities before going on to the next. Occasionally a quite striking phrase would come up, but on the whole I was not at all impressed.

“However, Gilbert explained that this was only a trial run and that the main circuits had not yet been set up. When they were, Ludwig would be far more selective: at the moment, he was playing everything that came along —he had no sense of discrimination. When he had ac­quired that, then the possibilities were limitless.

“That was the last time I ever saw Gilbert Lister. I had arranged to meet him at the lab about a week later, when he expected to have made substantial progress. As it hap­pened, I was about an hour late for my appointment. And that was very lucky for me. . . .

“When I got there, they had just taken Gilbert away. His lab assistant, an old man who’d been with him for years, was sitting distraught and disconsolate among the tangled wiring of Ludwig. It took me a long tune to dis­cover what had happened, and longer still to work out the explanation.

“There was no doubt of one thing. Ludwig had finally worked. The assistant had gone off to lunch while Gilbert was making the final adjustments, and when he came back an hour later the laboratory was pulsing with one long and very complex melodic phrase. Either the machine had stopped automatically at that point, or Gilbert had switched it over to REPEAT. At any rate, he had been listening, for several hundred times at least, to that same melody. When his assistant found him, he seemed to be in a trance. His eyes were open yet unseeing, his limbs rigid. Even when Ludwig was switched off, it made no difference. Gilbert was beyond help.

“What had happened? Well, I suppose we should have thought of it, but it’s so easy to be wise after the event. It’s just as I said at the beginning. If a composer, work­ing merely by rule of thumb, can produce a melody which can dominate your mind for days on end, imagine the effect of the Ultimate Melody for which Gilbert was searching! Supposing it existed—and I’m not admitting that it does—it would form an endless ring hi the memory circuits of the mind. It would go round and round forever, obliterating all other thoughts. All the cloying melodies of the past would be mere ephemerae compared to it. Once it had keyed into the brain, and distorted the cir­cling waveforms which are the physical manifestations of consciousness itself—that would be the end. And that is what happened to Gilbert.

“They’ve tried shock therapy—everything. But it’s no good; the pattern has been set, and it can’t be broken. He’s lost all consciousness of the outer world, and has to be fed intravenously. He never moves or reacts to ex­ternal stimuli, but sometimes, they tell me, he twitches in a peculiar way as if he is beating time. . . .

“I’m afraid there’s no hope for him. Yet I’m not sure if his fate is a horrible one, or whether he should be en­vied. Perhaps, in a sense, he’s found the ultimate reality that philosophers like Plato are always talking about. I really don’t know. And sometimes I find myself wonder­ing just what that infernal melody was like, and almost wishing that I’d been able to hear it perhaps once. There might have been some way of doing it in safety: remem­ber how Ulysses listened to the song of the sirens and got away with it . . .? But there’ll never be a chance now, of course.”

“I was waiting for this,” said Charles Willis nastily. “I suppose the apparatus blew up, or something, so that usual there’s no way of checking your story.”

Harry gave him his best more-in-sorrow-than-in-anger look.

“The apparatus was quite undamaged,” he said se­verely. “What happened next was one of those completely maddening things for which I shall never stop blaming myself. You see, I’d been too interested in Gilbert’s ex­periment to look after my firm’s business in the way that I should. I’m afraid he’d fallen badly behind with his payments, and when the Accounts Department discovered what had happened to him they acted quickly. I was only off for a couple of days on another job, and when I got back, do you know what had happened? They’d pushed through a court order, and had seized all their property. Of course that had meant dismantling Ludwig: when I saw him next he was just a pile of useless junk. And all because of a few pounds! It made me weep.”

“I’m sure of it,” said Eric Maine. “But you’ve forgotten Loose End Number Two. What about Gilbert’s assistant? He went into the lab while the gadget was going full blast. Why didn’t it get him, too? You’ve slipped up here, Harry.”

H. Purvis, Esquire, paused only to drain the last drops from his glass and to hand it silently across to Drew.

“Really!” he said. “Is this a cross-examination? I didn’t mention the point because it was rather trivial. But it explains why I was never able to get the slightest inkling of the nature of that melody. You see, Gilbert’s assistant was a first-rate lab technician, but he’d never been able to help much with the adjustments to Ludwig. For he was one of those people who are completely tone-deaf. To him, the Ultimate Melody meant no more than a couple of cats on a garden wall.”

Nobody asked any more questions: we all, I think, felt the desire to commune with our thoughts. There was a long, brooding silence before the “White Hart” resumed its usual activities. And even then, I noticed, it was every bit of ten minutes before Charlie started whistling “La Ronde” again.